Raise your Aqara Water Leak Sensor off the shower tray to allow water to run freely from it after the shower is turned off. This allows the sensor to switch between “wet” and “dry” states very quickly, as no water is allowed to pool around the electrodes, prolonging the wet state.

Legs are in the form of bolts to allow adjustable height. You want it low enough to trigger when water pools in the shower tray when the shower is running, but high enough for water to freely run away when the shower stops.